The present invention is generally directed to toners, and imaging processes thereof, and more specifically the present invention is directed to imaging and printing processes with a mixture of encapsulated toner compositions and toners free of encapsulation including those comprised of resin, pigment, optional additives, and wherein the toners free of encapsulation can be obtained by known melt blending processes, and wherein the mixture of toners are particularly useful for generating documents such as personal checks which are subsequently processed in reader/sorters. In one embodiment of the present invention there are provided processes for generating documents, such as checks, including for example divided checks, turn around documents such as invoice statements like those submitted to customers by American Express and VISA, corporate checks, highway tickets, rebate checks, other documents with magnetic codes thereon, and the like, with no or minimal toner smearing and excellent fixing characteristics. More specifically, in one embodiment the process of the present invention is accomplished with a mixture of an encapsulated toner and a toner free of encapsulation, and wherein image smearing and offsetting of the toner mixture to read and write heads, including offsetting to the protective foil that may be present on the aforesaid heads in magnetic ink character recognition processes and apparatus inclusive of, for example, the read and write heads present in MICR (magnetic ink character recognition) reader/sorters, such as the commercially available IBM 3890.TM., NCR 6780.TM., reader/sorters from Burroughs Corporation, and the like is substantially avoided or minimized. Some of the reader/sorter printers contain protective foils thereon, reference for example the IBM 3890.TM., and the problems associated with such protective foils as illustrated herein with respect to read and write heads with no foils are alleviated with the toner mixture and processes of the present invention. Accordingly, with the processes utilizing the toner mixture compositions the problems of image smearing to, and offsetting from the read and write heads in magnetic ink character recognition apparatuses is substantially eliminated. Moreover, in another embodiment the present invention is directed to improved economical processes for generating documents such as personal checks suitable for magnetic image character recognition wherein image smearing and toner offsetting, including offsetting to read and/or write heads including those with protective foils thereon or unprotected heads as indicated herein, can be avoided when such documents are processed in the aforementioned reader/sorters. The toner compositions of the present invention are also useful in the Xerox Corporation 9700/8700 wherein image smearing and image fixing can be improved.
Toner offset is eliminated or minimized with the processes of the present invention, it is believed, primarily because of the presence of the mixture of encapsulated and nonencapsulated toners. Offset results from, for example, the developed toner image being removed from the MICR (magnetic ink character recognition) document, such as a check, to the read and/or write heads contained in MICR readers such as the IBM 3890.TM. and the NCR 6780.TM.. When the aforesaid offset is eliminated or substantially reduced, the problem of image smearing onto the MICR documents, such as personal checks, is also avoided. By offset as used herein is meant an embodiment of the present invention that the toner, or toner mixture is released from the document, such as personal checks, and transfers and sticks to the aforementioned read and/or write heads. As a result, toner is removed from the checks, or other documents as illustrated herein primarily in a continuous manner causing image smearing, and substantially preventing the characters on the checks from being read magnetically and thus rejected in most instances. With the processes of the present invention, in embodiments image offset to protective foils as are contained in some reader/sorters, for example the IBM 3890.TM., may be reduced by a factor of 10, or eliminated. Also, with toner buildup on the read/write heads, after passing 1 to 500 checks, or more through the reader/sorter, the excess toner is released to the check document being processed causing image smearing, which is avoided or minimized with the processes of the present invention.
With further respect to the present invention, the process is particularly applicable to the generation of documents including personal checks, which have been fused with pressure roll fusers. Pressure fixing, such as that incorporated into the Xerox Corporation 4060.TM. machine, and Delphax S6000.TM. ionographic printer, are particularly useful with the processes of the present invention. In addition, fusing systems where heat is used, particularly in combination with pressure, for example where the above mentioned printers have been modified, by heating the pressure roll, or by the addition of a subsequent heat fusing system comprised of two rolls, are also applicable. Examples of specific fusing systems that may be added, for example, are those incorporated in the Xerox Corporation 1090.TM. or the Xerox Corporation 5090.TM. copiers, suitably modified if necessary to provide a fusing temperature in the range required for the encapsulated toner. Fuser roll temperatures of about 100.degree. C. to about 165.degree. C. are suitable in embodiments of the present invention.
The documents, including the personal checks mentioned herein, can be obtained, for example, by generating a latent image thereon and subsequently developing the image, reference U.S. Pat. No. 4,517,268, the disclosure of which is totally incorporated herein by reference, with the toner mixture illustrated herein. The developed image that has been created, for example, in the Xerox Corporation 4060.TM. printer, contains thereon, for example, the characters zero, 1, 2, 3, 4, 5, 6, 7, 8, and 9, and up to four symbols (E-13B and CMC-7 font), which characters are magnetically readable by the IBM 3890.TM., or other similar apparatus. One of the problems avoided with the processes of the present invention is to eliminate or reduce the offsetting of the toner as indicated herein to the read and write heads in the apparatus selected for this purpose, such as the IBM 3890.TM.. The imaging methods of the present invention are utilized in systems wherein pressure fusing is selected, reference the Delphax S6000.TM. and Xerox 4060.TM..
In one embodiment, the present invention is directed to MICR processes wherein there is selected a toner mixture comprised of an encapsulated toner composition comprised of a core comprised of a polymer including a silane modified polymer resin, magnetite and a polymeric shell thereover preferably prepared by interfacial polymerization; and a toner comprised of resin, wax, such as a solid wax with a melting point of from about 80.degree. C. to about 180.degree. C., magnetite, and optional additives, which toner is free of encapsulation. Another specific embodiment of the present invention relates to MICR processes with a mixture of toners as illustrated herein, and wherein the encapsulated toner compositions are comprised of a core comprised of a silane-modified polymer resin and magnetite particles, which core is encapsulated by a polymeric coating such as a polyurea, polyurethane, polyamide, polyester, or mixtures thereof.
In a patentability search report the following U.S. Patents were listed: U.S. Pat. No. 4,535,049 relating to a single magnetic toner with a combination of a binder resin and wax, see for example column 3, lines 6 to 29; U.S. Pat. Nos. 4,409,312 and 4,569,896 which disclose the combination of wax with a binder resin in a magnetic toner; 4,517,628 relating to MICR process and toners, and mentioned herein; and 4,555,466 relating to a toner which combines a wax with a binder. The disclosures of each of these patents are totally incorporated herein by reference.
There are mentioned as prior art the following U.S. Pat. Nos. 4,770,968 directed to polysiloxane butadiene terpolymer toner resins, reference for example column 4, and note the formulas of FIGS. 1 to 6, including FIG. 2B, which toners can be selected wherein silicone release oils are avoided, with no apparent teaching in this patent directed to encapsulated toners; 4,814,253 directed to encapsulated toners comprised of domains containing a polymer component having dispersed therein a release composition and thereover a host resin component comprised of toner resin particles and pigment particles, see for example the Abstract of the Disclosure and column 4, and note column 4 wherein there is illustrated as one of the components of the encapsulated toner domains comprised of styrene butadiene block polymers such as Kraton, styrene copolymers, or styrene siloxanes, which components have entrapped or dissolved therein mineral oils or silicon oils; and as background interest U.S. Pat. No. 4,430,408 relating to developer compositions containing a fluorene modified alkyl siloxane and a surface treatment carbon black, reference the Abstract of the Disclosure for example; U.S. Pat. No. 4,758,491 relating to dry toner and developer compositions with a multiphase polyorgano siloxane block or graft condensation copolymer, which provides polyorgano siloxane domains of a particular size and concentration at the toner particle surfaces; U.S. Pat. No. 4,820,604 directed to toner compositions comprised of resin particles, pigment particles, and a sulfur containing organo polysiloxane wax such as those of the formulas illustrated in the Abstract of the Disclosure; U.S. Pat. No. 4,307,169 discloses microcapsular electrostatic marking particles containing a pressure fixable core, and an encapsulating substance comprised of a pressure rupturable shell, which shell is formed by an interfacial polymerization; and Japanese Patent Publication 60-073630 relating to MICR toners and processes. One shell prepared in accordance with the teachings of the '169 patent is a polyamide obtained by interfacial polymerization. In the '169 patent, it is indicated that when magnetite or carbon black is selected they must be treated in a separate process to prevent migration thereof to the oil phase.
Interfacial polymerization processes are known and described in British Patent Publication 1,371,179, the disclosure of which is totally incorporated herein by reference, which publication illustrates a method of microencapsulation based on in situ interfacial condensation polymerization. More specifically, this publication discloses a process which permits the encapsulation of organic pesticides by the hydrolysis of polymethylene polyphenylisocyanate, or toluene diisocyanate monomers. Also, the wall forming reaction disclosed in the aforementioned publication is initiated by heating the mixture to an elevated temperature at which point the isocyanate monomers are hydrolyzed at the interface to form amines, which in turn react with unhydrolyzed isocyanate monomers to enable the formation of a polyurea microcapsule wall.
Moreover, there are disclosed in U.S. Pat. No. 4,407,922, the disclosure of which is totally incorporated herein by reference, interfacial polymerization processes for pressure sensitive toner compositions comprised of a blend of two immiscible polymers selected from the group consisting of certain polymers as a hard component, and polyoctadecylvinylether-co-maleic anhydride as a soft component.
Also of interest are U.S. Pat. Nos. 4,517,268, mentioned herein, relating to xerographic toners for MICR printing; 4,268,598 which discloses a nonencapsulated magnetic toner for the printing of machine readable legends; 4,748,506 relating to magnetic encapsulated toners, see column 4, wherein there is mentioned, for example, Columbian Mapico Black, and Bayferrox magnetites; and 3,627,682; 4,439,510; 4,536,462 and 4,581,312, which patents disclose, for example, encapsulated toners with magnetites. The disclosures of each of the aforementioned patents are totally incorporated herein by reference.
Disclosed in U.S. Pat. No. 5,045,422 entitled Encapsulated Toner Compositions, the disclosure of which is totally incorporated herein by reference, are encapsulated compositions containing cores comprised of a fluorocarbon and a monomer or monomers. More specifically, there is illustrated in the aforementioned patent an encapsulated toner composition comprised of a core with a fluorocarbon-incorporated resin binder, pigment or dyes, and a polymeric shell; and an encapsulated toner composition comprised of a core comprised of a fluorocarbon-incorporated resin binder derived from the copolymerization of an addition-type monomer and a functionalized fluorocarbon compound represented by Formula (I), wherein A is a structural moiety containing an addition-polymerization functional group; B is a fluorine atom or a structural moiety containing an addition-polymerization functional group; and x is the number of difluoromethylene functions, pigment or dyes, and a polymeric shell. Also, illustrated in U.S. Pat. No. 5,013,630 entitled Encapsulated Toner Compositions, the disclosure of which is totally incorporated herein by reference, is an encapsulated toner composition comprised of a core comprised of pigments or dyes, and a polysiloxane-incorporated core binder resin, which core is encapsulated in a shell. In U.S. Ser. No. 445,221 there are illustrated processes with encapsulated toner compositions that are useful for generating documents inclusive of personal checks, which documents are subsequently processed in reader/sorter devices as illustrated herein. More specifically, there are illustrated in the aforementioned copending application processes for generating documents, which comprise the formation of images, such as latent images with a printing device especially devices generating from about 8 to about 135 prints per minute; developing the image with an encapsulated toner composition; subsequently transferring the developed image to a suitable substrate; permanently affixing the image thereto; and thereafter processing the documents in reader/sorters wherein image offsetting and image smearing are avoided or substantially reduced. Some examples of the aforementioned process wherein an encapsulated toner is not selected are illustrated in U.S. Pat. No. 4,517,268, especially column 3; the disclosure of this patent is totally incorporated herein. Examples of high speed ionographic printers, which can be utilized for the process of the copending application, the disclosure of which is totally incorporated herein by reference, include the Delphax S6000.TM. printers and the commercially available Xerox Corporation 4060.TM.. Thereafter, the formed documents with magnetic characters thereon are processed in reader/sorter apparatuses as illustrated herein.
One specific embodiment of the aforementioned copending application is directed to a process for obtaining images, which comprises the generation of a latent image and developing the latent images with a toner composition comprised of a core comprised of a polymer and pigment, such as magnetite, which core is encapsulated in a polymeric shell. In another embodiment of the copending application, there is provided an ionographic process which comprises the generation of a latent image comprised of characters; developing the image with an encapsulated magnetic toner comprised of a core comprised of a polymer and magnetite with a coercivity of from about 80 to about 250 Oersteds, and a remanence of from about 20 to about 70 Gauss, and wherein the core is encapsulated within a polymeric shell; and subsequently providing the developed image with magnetic ink characters thereon to a reader/sorter device whereby toner offsetting and image smearing is minimized in said device. Also encompassed by the aforementioned copending application are electrophotographic, especially xerographic, imaging and printing processes wherein the encapsulated toners disclosed herein are selected. Examples of suitable core polymers illustrated in the copending application and present in various effective amounts such as, for example, from about 20 percent by weight to about 40 percent by weight, include pressure fixable adhesive materials possessing a low glass transition temperature of from about -170.degree. C. to about +25.degree. C., and preferably from -100.degree. C. to -10.degree. C. can be selected for the toners of the present invention. The core polymer can be obtained by the in situ free radical polymerization of a core monomer or monomers up to, for example, 10, including acrylates and methacrylates, such as butyl acrylate, propyl acrylate, benzyl acrylate, pentyl acrylate, hexyl acrylate, cyclohexyl acrylate, dodecyl acrylate, ethoxy propyl acrylate, heptyl acrylate, isobutyl acrylate, methyl butyl acrylate, 2-ethoxyethyl acrylate, 2-butoxyethyl acrylate, 2-ethylbutyl acrylate, 2-ethylhexyl acrylate, 2-methoxypropyl acrylate, nonyl acrylate, octyl acrylate, m-tolyl acrylate, dodecyl methacrylate, hexyl methacrylate, isodecyl methacrylate, 2-ethoxyethyl methacrylate, octyl methacrylate, decyl methacrylate, tetradecyl methacrylate, octadecyl methacrylate, styrene, dodecyl styrene, hexyl methyl styrene, nonyl styrene, tetradecyl styrene, or other known vinyl monomers, reference for example U.S. Pat. No. 4,298,672, the disclosure of which is totally incorporated herein by reference, mixtures thereof; and the like. The core monomer is polymerized to obtain a polymer with, for example, a number average molecular weight (M.sub.n) of from about 15,000 to about 100,000, and preferably from about 25,000 to about 60,000; and a ratio (M.sub.w /M.sub.n) of weight average molecular weight/number average molecular weight of greater than 2, and preferably from about 2.5 to about 4.0. Preferred core monomers, which are subsequently polymerized, include dodecyl methacrylate, octadecyl methacrylate, styrene, n-butyl acrylate and mixtures thereof.
There is a need for magnetic image character recognition (MICR) toners and processes enabling the generation of documents, such as personal checks, wherein toner offsetting and image smearing is avoided, or minimized. There is also a need for the generation of developed images including the generation of personal checks in laser printers or ionographic printers utilizing magnetic ink character recognition technology, wherein toner offset to protective foils present on the read and write heads is avoided or minimized, and image smearing is avoided or minimized. In addition, there is a need for MICR processes with a mixture of toners comprised of nonencapsulated toners, and encapsulated toners wherein toner offsetting to protective foils, and image smearing on documents generated is reduced or eliminated. There is also a need for MICR processes where the printed MICR characters do not offset to vinyl surfaces as, for example, where the MICR characters of a check document are in contact with window envelopes or vinyl check book covers. The processes of the present invention reduce or eliminate the offset to vinyl surfaces.
With the processes of the present invention, it is preferred in embodiment that the encapsulated toners have high, for example 40 to 65 weight percent of magnetite, and thus relatively low remanence magnetites are selected to provide the desired magnetic signal strength in the MICR reader. The aforementioned magnetite iron oxides can be more economical than the higher remanence magnetites which are selected for many MICR toners in which the loadings are substantially lower, for example 30 percent. There is a need for encapsulated toner compositions with many of the advantages illustrated herein. More specifically, there is a need for a mixture of toners and MICR processes thereof wherein image ghosting is eliminated or minimized. Also, there is a need for MICR processes and toners thereof which offer quality images with good fixing levels, for example over 70 percent at low fixing pressure of, for example, 2,000 psi. Moreover, there is a need for a mixture of toners, wherein image ghosting, and the like are avoided or minimized. Also, there is a need for a MICR toner mixture that has been surface treated with additives such as carbon blacks, graphite or the like to impart to their surface certain conductive characteristics such as providing a volume resistivity of from about 1.times.10.sup.3 ohm-cm to about 1.times.10.sup.8 ohm-cm. Furthermore, there is a need for a MICR toner mixture wherein surface additives such as metal salts or metal salts of fatty acids and the like are utilized to assist in the release of the images from the imaging component to the paper substrate.